Electric blind apparatus

Abstract

When a raising switch (21) or a lowering switch (23) is operated in an electric blind apparatus, an MPU (34) rotates a geared motor (4) so that a take drum (37) winds up or unwinds a lifting tape (10) to raise/lower vanes (13) of a blind. Upon rotation of the take-up drum, a photointerrupter (38) generates pulse signals and the MPU counts the pulse signals to judge a vertical position of the blind. When an opening or closing switch (24, 26) is operated, the MPU rotates the geared motor so that a ladder drum (39) is followingly rotated to wind up one of ladder cords (11) fixed to the ladder drum, thereby to adjust an open/close angle of the vanes. Following rotation of the ladder drum, a photointerrrupter (41) supplies pulse signals to the MPU, which in turn counts the pulse signals to judge the open/close angle of the vanes.

What is claimed is: 
     
       1. An electric blind apparatus for raising/lowering a plurality of strip-shaped vanes forming a blind by driving an electric motor, said electric blind apparatus comprising: an electric motor; a plurality of strip-shaped vanes;   a cord-like member for raising/lowering said plurality of vanes by driving force of said electric motor;   vane opening/closing means for simultaneously opening/closing said plurality of vanes by driving force of said electric motor;   lifting means being rotated in response to rotation of said electric motor to wind or unwind said cord-like member for raising/lowering said blind, said lifting means includes a rotary drum driven by said electric motor for winding or unwinding an end of said cord-like member;   rotational speed detecting means for detecting the rotational speed of the rotary drum;   command means for commanding raising/lowering and stoppage of said blind and opening/closing of said plurality of vanes; and   control means for driving said electric motor in response to a raising/lowering command from said command means   to raise/lower said blind by said lifting means and driving said electric motor by an opening/closing command from said command means to open/close said plurality of vanes by said vane opening/closing means, said control means further including vertical position judging means for judging the vertical position of said blind by counting detecting output of said rotational speed detecting means.   
     
     
       2. The electric blind apparatus in accordance with claim 1, further including lower limit set means for setting the lower limit position of said blind, said control means including means for stopping said electric motor in response to a judgement, being made by said vertical position judging means, of downward movement of said blind to said lower limit position set by said lower limit set means.   
     
     
       3. The electric blind apparatus in accordance with claim 2, further including power supply detecting means for detecting power supply, said control means including means for rotating said electric motor until said blind is lowered to said lower limit position set by said lower limit set means in response to detection of said power supply by said power supply detecting means.   
     
     
       4. The electric blind apparatus in accordance with claim 1, further including rotational speed judging means for judging whether detection outputs from said rotational speed detecting means are provided by a prescribed number within a predetermined period from supply of a command for raising/lowering said blind from said command means, said control means including means for stopping said electric motor in response to a judgement, being made by said rotational speed judging means, that said detection outputs fail to be provided in said prescribed number.   
     
     
       5. The electric blind apparatus in accordance with claim 1, further including raising position detecting means for detecting that said blind is raised to a maximum raising position, said control means including means for stopping said electric motor in response to a judgement, being made by said raising position detecting means, that said blind is raised to said maximum raising position.   
     
     
       6. The electric blind apparatus in accordance with claim 1, wherein said electric motor includes a DC motor having terminals being supplied with DC driving voltage from said control means, said control means including means for causing a short across said terminals of said DC motor during stoppage of said DC motor.   
     
     
       7. An electric blind apparatus for raising/lowering a plurality of strip-shaped vanes forming a blind by driving an electric motor, said electric blind apparatus comprising: an electric motor; a plurality of strip-shaped vanes;   a first cord-like member for raising/lowering said plurality of vanes by driving force of said electric motor;   vane opening/closing means for simultaneously opening/closing said plurality of vanes by driving force of said electric motor, said vane opening/closing means further including,   a pair of second cord-like members coupled to shorter-side ends of each of said plurality of vanes,   a rotary drum to which ends of said second cord-like members are fixed, said rotary drum being rotated by driving force of said electric motor for winding one of said pair of second cord-like members, thereby simultaneously adjusting the open/close angle of said plurality of vanes;   lifting means being rotated in response to rotation of said electric motor to wind or unwind said first cord-like member for raising/lowering said blind;   command means for commanding raising/lowering and stoppage of said blind and opening/closing of said plurality of vanes;   pulse signal generating means for generating pulse signals in response to rotation of said rotary drum; and   control means for driving said electric motor in response to a raising/lowering command from said command means to raise/lower said blind by said lifting means and driving said electric motor by an opening/closing command from said command means to open/close said plurality of vanes by said vane opening/closing means, said control means further including open/close angle judging means for rotating said rotary drum by said electric motor in response to an opening/closing command from said command means and for counting said pulse signals generated from said pulse signal generating means to judge the open/close angle of said vanes.   
     
     
       8. The electric blind apparatus in accordance with claim 7, further including memory means for storing said open/close angle of said vanes judged by said open/close angle judging means, said control means including means for controlling said electric motor to make said memory means store said open/close angle judged by said open/close angle judging means in response to a command from said command means and thereafter to raise/lower said blind.   
     
     
       9. The electric blind apparatus in accordance with claim 8, wherein said control means includes means for stopping said electric motor in response to a stop command from said command means and thereafter driving said electric motor so that said open/close angle judged by said open/close angle judging means coincides with said open/close angle stored in said memory means, thereby to open/close said vanes by said vane opening/closing means.   
     
     
       10. An electric blind apparatus for raising/lowering a plurality of strip-shaped vanes forming a blind by driving an electric motor, said electric blind apparatus comprising: an electric motor; a plurality of strip-shaped vanes;   a cord-like member for raising/lowering said plurality of vanes by driving force of said electric motor;   vane opening/closing means for simultaneously opening/closing said plurality of vanes by driving force of said electric motor;   lifting means being rotated in response to rotation of said electric motor to wind or unwind said cord-like member for raising/lowering said blind;   command means for commanding raising/lowering and stoppage of said blind and opening/closing of said plurality of vanes;   a movable member which is moved horizontally in response to tension on said cord-like member;   looseness detecting means for detecting horizontal movement of said movable member following loosening of said cord-like member; and   control means for driving said electric motor in response to a raising/lowering command from said command means to raise/lower said blind by said lifting means and driving said electric motor by an opening/closing command from said command means to open/close said plurality of vanes by said vane opening/closing means, said control means further includes means for stopping said electric motor in response to detection of looseness of said cord-like member by said control means.   
     
     
       11. The electric blind apparatus in accordance with claim 10, wherein said movable member detecting means includes: a light emitting part for emitting light, and   a light receiving part provided opposite said light emitting part by a prescribed space for detecting looseness of said cord-like member when said light from said light emitting part is intercepted in response to horizontal movement of said movable member.   
     
     
       12. An electric blind apparatus for raising/lowering a plurality of vanes of a blind and adjusting the angle of said vanes in response to rotation of an electric motor, said electric blind apparatus comprising: an electric motor; a plurality of strip-shaped vanes;   lifting means for winding or unwinding a cord-like member coupled to said plurality of vanes in response to rotation of said motor to raise/lower said blind;   vertical position detecting means for detecting the vertical position of said blind;   angle detecting means for detecting the angle of said vanes;   trouble detecting means for detecting trouble in raising/lowering of said cord-like member;   upper limit detecting means for detecting that said blind is raised to an upper limit position;   lower limit set means for setting a lower limit position for said blind;   command means for commanding raising and lowering of said blind and opening/closing of said vanes; and   control means for raising said blind by said lifting means in response to a raising command from said command means, stopping said electric motor in response to a detection signal from said upper limit detecting means, lowering said blind by said lifting means in response to a lowering command from said command means, stopping said electric motor when a vertical position of said blind detected by said vertical position detecting means coincides with said lower limit position set by said lower limit set means, stopping said electric motor when a detection signal is outputted from said trouble detecting means during raising/lowering of said blind and controlling said electric motor in response to detection output from said angle detecting means in response to supply of a command for opening/closing said vanes from said command means to control the angle of said vanes.   
     
     
       13. An electric blind apparatus for raising/lowering a plurality of strip-shaped vanes forming a blind by driving and electric, said electric motor blind apparatus comprising: an electric motor; a plurality of strip-shaped vanes;   a cord-like member for raising/lowering said plurality of vanes by driving force of said electric motor, said cord-like member includes indicators for optically detecting the vertical position of said blind, said plurality of vanes each including a holes for receiving said cord-like member;   vane opening/closing means for simultaneously opening/closing said plurality of vanes by driving force of said electric motor;   lifting means being rotated in response to rotation of said electric motor to wind or unwind said cord-like member for raising/lowering said blind;   a member provided under said plurality of vanes connected to an end of said cord-like member, said member pressing said plurality of vanes sequentially upwardly from a lower part thereof upon rotation of said lifting means during raising of said blind;   command means for commanding raising/lowering and stoppage of said blind and opening/closing of said plurality of vanes;   indicator means for detecting said indicators of said cord-like member; and   control means for driving said electric motor in response to a raising/lowering command from said command means to raise/lower said blind by said lifting means and driving said electric motor by an opening/closing command from said command means to open/close said plurality of vanes by said vane opening/closing means, said control means further including means for judging the vertical position of said blind in response to detection output from said indicator means.